1. Field of the Invention
The present invention relates to a component for linear guideway and method for making the same, and more particularly to an end cap or bolt cover which is made of bulk molding compound, or performing a metal inserting member with return path, and then forming a component directly on the inserting member by thermal setting bulk molding compound, so as to form an integral end cap with high strength, speed while low cost.
2. Description of the Prior Art
Most of the components (such as the end cap) of the linear guideway used on a machine working in a high temperature environment are made by wax-lost casting in order to have a high temperature resistance property. Such a wax-lost casting is very complicated, which comprises the following processes:
Wax injection: forming a shell mold by wax injection;
Wax pattern assembly: assembling and designing a casting runner;
Dipping and sand sprinkling: Dipping the component into ceramic slurry and sprinkling sands on it. Dipping and sand sprinkling can only be carried out to form a new layer of ceramic layer and sands after the previous layer of ceramic slurry with the sands cures, and such a process must be repeated for several times since there are plural layers to be done;
Lost wax: melting the wax off the shell mold and the runner to form a hollow shell mold with a cavity;
Preheat: preheat the shell mold with high temperature;
Melting and pouring: melting metal and pouring melted metal liquid into the cavity of the shell mold, and waiting till it cools down;
Shell breaking: breaking the shell and taking out the semifinal products and cutting off the connection between the runners of the semifinal products;
Sand blasting: sand blasting the surface of the semifinal products;
CNC processing: processing the semifinal products with CNC;
Final products: obtaining final products.
During the dipping and sand sprinkling, each layer of ceramic and sand should take almost one day to dry, and then another layer of dipping and sand sprinkling can be carried out, and such operation should be repeated for several times until it reaches the predetermined thickness. Normally, the process of dipping and sand sprinkling should be repeated for 7 times, that is to say that it takes almost 2 months to carry out all the above processes before obtaining a final product. Furthermore, the dimension tolerance of the end cap or other parts made by such technology is almost ±0.05 mm, which is larger than the acceptable tolerance of the linear guideway. Hence, CNC is required to further process the end cap or other parts to the acceptable size, which is not only time consuming but also cost intensive.
On the other hand, it should wait a certain period of time for the product to cool down after melting and pouring until, otherwise, it is likely to produce heat stress which will cause unexpected defects in internal structure of the product, substantially affecting the service life of the product.
In addition, the rolling members are most likely to produce local high temperature when rolling through the return path of the end cap, as a result, the end cap is likely to have tiny cracks at this high temperatures area and will expand outward, and such tiny cracks may impair the structural strength of the end cap.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.